Temporal evolution of gamma activity in human cortex during an overt and covert word repetition task.
Temporal evolution of gamma activity in human cortex during an overt and covert word repetition task.
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DOI：
10.3389/fnhum.2012.00099
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发表时间：
2012
影响因子：
2.9
通讯作者：
Schalk G
中科院分区：
文献类型：
--
作者：
Leuthardt EC;Pei XM;Breshears J;Gaona C;Sharma M;Freudenberg Z;Barbour D;Schalk G
几位科学家提出了不同的语言皮层处理模型。传统上，参与语言的区域被认为是模块化的，具有线性激活序列。最近，现代理论模型已经为语音处理的各个阶段提出了一个更分层和分布式的解剖区域相互作用。传统的成像技术只能确定皮层激活的位置或时间，这阻碍了这些模型的进一步评估和完善。在这项研究中，我们利用记录从表面的大脑[皮层电图（ECoG）]，它可以准确地检测到的位置和时间的皮层激活，研究的时间过程中的ECoG高伽马（HG）调制的显性和隐性的单词重复任务不同的皮层区域。对于明显的文字生产，我们的研究结果表明，大量的大脑侧裂周皮层激活早期的知觉阶段的任务，通过文字清晰度保持。然而，这种广泛的激活是衰减在表达阶段的内隐词重复。在不同的重复任务中，大脑侧裂周区域内不同皮质部位的利用率在激活程度上有所不同，这取决于提供的刺激（听觉或视觉线索）以及单词是说出来还是想象出来。总之，这些数据支持先前用功能成像描述的当前语音模型。此外，这项研究表明，广泛的perisylvian语音网络激活早期，并保持阈上激活整个单词重复任务，似乎是调制的需求，不同的条件。
Several scientists have proposed different models for cortical processing of speech. Classically, the regions participating in language were thought to be modular with a linear sequence of activations. More recently, modern theoretical models have posited a more hierarchical and distributed interaction of anatomic areas for the various stages of speech processing. Traditional imaging techniques can only define the location or time of cortical activation, which impedes the further evaluation and refinement of these models. In this study, we take advantage of recordings from the surface of the brain [electrocorticography (ECoG)], which can accurately detect the location and timing of cortical activations, to study the time course of ECoG high gamma (HG) modulations during an overt and covert word repetition task for different cortical areas. For overt word production, our results show substantial perisylvian cortical activations early in the perceptual phase of the task that were maintained through word articulation. However, this broad activation is attenuated during the expressive phase of covert word repetition. Across the different repetition tasks, the utilization of the different cortical sites within the perisylvian region varied in the degree of activation dependent on which stimulus was provided (auditory or visual cue) and whether the word was to be spoken or imagined. Taken together, the data support current models of speech that have been previously described with functional imaging. Moreover, this study demonstrates that the broad perisylvian speech network activates early and maintains suprathreshold activation throughout the word repetition task that appears to be modulated by the demands of different conditions.
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影响因子：
3.2
作者：
Chang EF;Edwards E;Nagarajan SS;Fogelson N;Dalal SS;Canolty RT;Kirsch HE;Barbaro NM;Knight RT
通讯作者：
Knight RT
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14.5
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通讯作者：
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Billingsley-Marshall, Rebecca L.;Clear, Trustin;Papanicolaou, Andrew C.
通讯作者：
Papanicolaou, Andrew C.
影响因子：
4.8
作者：
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通讯作者：
WINN, HR